This disclosure is generally directed to drum and layered imaging members, photoreceptors, photoconductors, and the like. More specifically, the present disclosure is directed to multilayered flexible or belt imaging members or devices comprised of an optional supporting medium like a substrate, a first photogenerating layer, a second photogenerating layer, and a charge transport layer, inclusive of a plurality of charge transports layers, such as a first charge transport layer and a second charge transport layer, an optional adhesive layer, an optional hole blocking, or undercoat layer, an optional overcoating layer, and wherein at least one of the charge transport layers contains at least one charge transport component, a polymer, or resin binder. The first photogenerating layer is in embodiments in contact with the supporting substrate and the second photogenerating layer, that is the first photogenerating layer can be situated between the supporting substrate and the second photogenerating layer, or the second photogenerating layer can be situated between the supporting substrate and the first photogenerating layer. More specifically, the first photogenerating layer is comprised of a phthalocyanine, such as a high sensitivity titanyl phthalocyanine Type V, generated, for example, by the processes as illustrated in copending application U.S. application Ser. No. 10/992,500, U.S. Publication No. 20060105254, the disclosure of which is totally incorporated herein by reference. The second photogenerating layer, which can be situated between the charge transport layer and the first photogenerating layer, or where the second photogenerating layer can be situated between the supporting substrate and the first photogenerating layer, which first layer is situated between the charge transport layer and the second photogenerating layer, can be comprised of a different phthalocyanine than is present in the first photogenerating layer, and yet more specifically, where the second photogenerating pigment can be a hydroxygallium phthalocyanine.
The photoconductors illustrated herein in embodiments possess minimal undesirable ghosting characteristics, and developed xerographic images of excellent quality. Additionally, in embodiments the photoconductors disclosed herein possess excellent and in a number of instances low Vr (residual potential), and allow the substantial prevention of Vr cycle up when appropriate; high stable sensitivity; low acceptable image ghosting characteristics; and desirable toner cleanability.
More specifically, there is illustrated herein in embodiments the incorporation into the first and second photogenerating layer dissimilar photogenerating pigments, such as a suitable phthalocyanine photogenerating pigment like a number of titanyl phthalocyanines, especially titanyl phthalocyanine Type V, a dihydroxygallium phthalocyanine, and at least one hole transport component layer thereover either the first photogenerating layer or the second photogenerating layer, permitting, for example, minimum ghosting characteristics in the developed images, and where the photosensitivity thereof is from about 10 to about 50 percent higher than that of a similar photoconductor containing a single layer with a photogenerating pigment of a hydroxygallium phthalocyanine Type V pigment.
Also included within the scope of the present disclosure are methods of imaging and printing with the photoconductors illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additives, reference U.S. Pat. Nos. 4,560,635; 4,298,697 and 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto. In those environments wherein the device is to be used in a printing mode, the imaging method involves the same operation with the exception that exposure can be accomplished with a laser device or image bar. More specifically, the imaging members and flexible belts disclosed herein can be selected for the Xerox Corporation iGEN3® machines that generate with some versions over 100 copies per minute. Processes of imaging, especially xerographic imaging and printing, including digital, and/or color printing, are thus encompassed by the present disclosure.
The photoconductors disclosed herein are in embodiments sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular from about 500 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the photoconductors disclosed herein are in embodiments useful in high resolution color xerographic applications, particularly high-speed color copying and printing processes, and wherein the outputs thereof possess minimal ghosting characteristics or improved ghosting characteristics as compared, for example, to a similar photoconductor with a single photogenerating layer containing a phthalocyanine.